Mortar between floor and first course?

[Attis]

Hello!
I'm in the middle of building my oven. I have just finsihed the cooking floor and I'm about to "lay" the first course. It will be a Neapolitan style oven with standing bricks for the first course.
However when I look at pictures on this site, most of them seems to have no or very little mortar between the first course and cooking floor.
Is there really no mortar och just a think layer?

My bricks will be standning on the cooking floor bricks, not on the outisde.

Regards
Attis

[CoyoteVB]

Re: Mortar between floor and first course?

There are a lot of posts suggesting no mortar between the floor and first course. some post suggest a thin paper layer between the floor and first course. Let it float, move and expand.

[stonecutter]

Re: Mortar between floor and first course?

Structurally speaking, it does nothing and the weight of the dome is all that is needed to keep things in place. A mortar layer between the floor and base can help if you don't have a level surface, but you can make that up in the upper courses.

[Attis]

Re: Mortar between floor and first course?

Thanks a lot.
Makes it a little easier also, only mortar on one side